ESPCI web site
ROOTSTOCK: Plant root development affected by soil mechanical stresses
see the link PhD_Proposal https://euraxess.ec.europa.eu/jobs/462078
The interaction between plant roots and soils is a wide and interdisciplinary issue involving many communities from biophysics, agronomy, soil science to civil engineering and geophysics. The presence of zones of high mechanical resistance in the soil is one of the most common physical limitations to soil exploration by roots, which has direct consequences on the healthy development of the plant. The root apex must exert a growth pressure to overcome the resistance to deformation of the surrounding soil or reorient its growth to bypass obstacles or strong soil layers.
In the PMMH laboratory, we developped model experimental systems to study how the root changes its growth when encountering a single or a collection of obstacles mimicking the mechanical heterogeneities in a soil. In particular we investigated the growth response of a root (i) pushing against a single obstacle such as a force sensor or (ii) growing inside a 3D-printed array of stiff obstacles. For instance, by coupling force (Fig. i1) and kinematic measurements under infra-red lighting (Fig. i2), we probed the force-growth relationship of a primary root contacting a stiff resisting obstacle, that mimics the strongest soil impedance variation encountered by a growing root.
Different subjects are possible around the interaction of roots with mechanical obstacles. One possible topic is 1) to investigate the response of the root to prescribed indentation steps to study its timedependant mechanical properties and 2) to decouple the mechanical and biological responses by using a feedback loop on the applied force on the root.
